[Mediastinoscopy in the staging of bronchial carcinoma--a critical assessment]

Non-small cell lung cancer: prognostic importance of positive FDG PET findings in the mediastinum for patients with N0-N1 disease at pathologic analysis

PURPOSE

To assess the prognostic implications of mediastinal positron emission tomographic (PET) findings in patients undergoing curative resection of non-small cell lung cancer (NSCLC) who have histologically negative mediastinal lymph nodes (LNs), with the hypothesis that positive findings at PET are prognostic even in patients with negative histologic findings in the LNs.

MATERIALS AND METHODS

Records of patients with a preoperative PET undergoing curative surgery, without adjuvant radiation, for pathologic T1-3N0-1 NSCLC at the University of North Carolina between 2000 and 2006 were reviewed as an institutional review board-approved HIPAA-compliant retrospective study. Ninety patients were evaluable (all histologically negative in mediastinum; 44 with both mediastinoscopy and surgery); 13 patients had positive mediastinal PET findings, and 77 had negative mediastinal PET findings. Local-regional and distant failure rates in patients with and those without mediastinal abnormalities at preoperative PET were compared by using logistic regression and log-rank tests.

RESULTS

Median follow-up was 54.3 months (range, 1-99 months). There were higher rates of local-regional (P = .001) and distant (P < .001) failure as well as death (P = .001) in patients with postive PET findings than in patients with negative findings. In multivariable analysis (adjusting for other prognostic factors), positive PET findings in the mediastinum remained prognostic for distant failure (P < .001, hazard ratio = 6.9) and were marginally prognostic for local-regional failure (P = .093, hazard ratio = 1.9).

CONCLUSION

Positive findings at preoperative PET in the mediastinum appear to have prognostic implications despite the mediastinal LNs being histologically negative. The high rate of local-regional and distant failure suggests that postoperative radiation therapy and/or chemotherapy may be particularly helpful in patients with positive mediastinal findings at preoperative PET.

Lymph node staging by means of positron emission tomography is less accurate in non-small cell lung cancer patients with enlarged lymph nodes: analysis of 1,145 lymph nodes

BACKGROUND

Despite documented superiority of integrated positron emission tomography-computerized tomography (PET-CT) over computerized tomography (CT) in lymph node staging in non-small cell lung cancer, little is known about the sensitivity, specificity and accuracy of integrated PET-CT among enlarged lymph nodes. We sought to assess if PET-CT is uniformly accurate among enlarged and non-enlarged lymph nodes.

METHODS

A retrospective review of 206 consecutive patients with histologically proven non-small cell lung cancer who underwent resection and/or mediastinoscopy in our centre over 30 months period was carried out. All these patients had pre-operative staging with integrated PET-CT as an adjunct to chest CT prior to resection and/or mediastinoscopy. Diabetic patients (BM>or=8.0 mmol/l) and those who received neo-adjuvant chemotherapy were excluded. The pathological results of all these cases were reviewed and correlated with those on CT and integrated PET-CT.

RESULTS

The sensitivity, specificity, accuracy, positive and negative predictive values were higher in integrated PET-CT than CT alone in all lymph nodes, whether N1 or N2. When lymph nodes were stratified by size, the sensitivity of PET-CT was significantly higher among enlarged (>1cm) than non-enlarged (<or=1cm) lymph nodes (74% vs. 40%, P<0.0001), but with a significantly lower specificity (81% vs. 98%, P<0.0001) and a lower accuracy (78% vs. 90%, P 0.008).

CONCLUSIONS

Integrated PET-CT remains superior to CT in nodal staging of non-small cell lung cancer. However, in the presence of enlarged lymph nodes, PET-CT becomes less specific, less accurate but more sensitive in detecting metastatic spread to the lymph nodes. Interpretation of PET-CT findings in NSCLC patients with enlarged lymph nodes (>1cm) should be with caution as the specificity of PET-CT is lower and its ability to detect truly negative nodes become reduced. NSCLC patients with enlarged nodes by CT criteria who are PET-CT negative may require cervical mediastinoscopy to rule out metastatic spread to these nodes. Prospective studies are warranted.

Endobronchial ultrasound guided transbronchial needle aspiration for staging of lung cancer

During the staging process of lung cancer, accurate mediastinal lymph node staging is one of the important factors which affect patient management. The purpose of the current study was to evaluate the usefulness of direct real-time endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) for staging and diagnosis of lung cancer in patients with mediastinal lymph nodes suspected of malignancy and to assess the impact of this method in patient management. One hundred and eight patients with mediastinal lymph nodes with known or suspected lung cancer were included. The convex probe EBUS integrated with a convex scanning probe on its tip was used in all cases. Final diagnosis was based on cytology, surgical results, and/or clinical follow-up. In 105 patients, EBUS-TBNA was successfully performed to obtain samples from 163 lymph nodes. With respect to the correct prediction of lymph node stage, EBUS-TBNA had a sensitivity of 94.6%, specificity of 100%, positive predictive value of 100%, negative predictive value of 89.5%, and diagnostic accuracy rate of 96.3%. In the 20 suspected lung cancer cases, mediastinal lymph node was used for tissue diagnosis of malignancy as well as staging. As a result of EBUS-TBNA, 29 mediastinoscopies, 8 thoracotomies, 4 thoracoscopies, and 9 CT-guided PCNB were avoided. The procedure was uneventful without complications. EBUS-TBNA is a safe and sensitive method for lymph node staging in patients with lung cancer. It spares invasive staging procedures which has a major impact on patient management.

Initial surgical staging of lung cancer

Many patients with early stage lung cancer (stage I and II) are curable by surgical resection. In patients with locally advanced disease surgery plays an important role in order to provide local tumor control. Therefore, the aim of all staging efforts in NSCLC must be to identify all patients, who might be potential candidates for a surgical approach. Current staging tools include imaging techniques like CT- and PET-scan, transthoracic, transbronchial or transeosophageal needle biopsies and finally surgical staging methods including mediastinoscopy and video-assisted thoracoscopic surgery (VATS). With respect to mediastinal lymph node staging, cervical mediastinoscopy is reported to have a sensitivity between 81 and 89%. This mainly due to the fact, that some lymph node levels (# 8, 9, 5, 6) are not accessible by the standard cervical approach. The morbidity and mortality of cervical mediastinoscopy is in experienced centers only minimal. In series with more than 1000 patients, the mortality was almost 0% and morbidity varied between 0.5 and 1%. Cervical mediastinoscopy can be performed also as an outpatient procedure. In addition to 'simple' lymph node staging, mediastinoscopy clarifies the local resectability of central tumors (T-factor). Currently, cervical mediastinoscopy is recommended by almost all scientific societies in patients with apparently resectable NSCLC who present with enlarged mediastinal lymph nodes of >1 cm in short axis diameter. Video-mediastinoscopy allows that the procedure gets even more standardized and preliminary data suggest that the sensitivity might be improved in comparison to conventional mediastinoscopy. Since VATS is widely accepted by the community of thoracic surgeons, it has become an important staging tool in many situations. VATS can be used to rule out or confirm a suspected contralateral lung metastasis. Furthermore, VATS is extremely useful to exclude malignant pleural effusions in otherwise operable patients. This examination can be done in the operating room immediately prior to formal thoracotomy. Additionally, VATS is effective to explore the local resectability in patients with suspected mediastinal infiltration or a lymphangiosis carcinomatosa within the mediastinum. VATS allows an accurate staging of more than 90% of the patients with suspected stage IIIB NSCLC. With respect to lymph node staging, VATS is complimentary to cervical mediastinoscopy because it helps to stage the lymph nodes in the A-P. window (#5, 6), as well as the lymph nodes paraesophageal (#8) and in the pulmonary ligament (#9). In conclusion, surgical staging methods provide a 100% specificity in combination with a high sensitivity and only a minimal morbidity. Currently, surgical staging is recommended by the majority of scientific societies for the staging of patients with apparently resectable NCSLC.

Radical video-assisted mediastinoscopic lymphadenectomy (VAMLA)--technique and first results

Exact pretherapeutic lymph node staging of lung cancer is of special importance for selecting patients for neoadjuvant therapy or for video-assisted thoracoscopic resection. Staging is usually performed by computerized tomography scan and mediastinoscopy. However, these methods do not reach the accuracy of open nodal dissection. Therefore, we developed a technique of radical video-assisted mediastinoscopic lymphadenectomy (VAMLA). In a prospective study, all VAMLA procedures were documented. Lymph nodes were counted and compared to open lymphadenectomy. In 40/46 patients, radical paratracheal and subcarinal dissection was achieved by VAMLA. An average number of 20.7 (5-60, SD 11.1) nodes was gained. This is comparable to our data from open lymphadenectomy.